Apple Mail or Gmail requires password to access Gmail.
Since updating to Sierra, my Apple Mail has not been able to log in to Gmail. At first, Mail asked for my Gmail password on every startup but, now it doesn't ask for the password and I can't find any place in Apple Mail or Internet Accounts to enter the password, I deleted the accounts and keychain stuff and everything was OK for a couple of days and now I am back to entering the password. I cannot upgrade above Sierra because the wonderful old iMac 2011 is at its limit supposedly.